


Happy Birthday

by orphan_account



Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Brother/Sister Incest, F/M, Hand Jobs, Mildly Dubious Consent, Multi, Sibling Incest, Underage Drinking, Underage Kissing, Underage Oral Sex, Vaginal Fingering
Language: English
Status: Completed
Published: 2014-02-26
Updated: 2014-02-26
Packaged: 2018-01-11 22:47:33
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,119
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1178874
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>It's your birthday weekend and your older brother Mycroft has returned home from Uni to celebrate it with you. The fact that he has brought a friend with him isn't the only surprise he has in store for you.</p>
            </blockquote>





	Happy Birthday

**Author's Note:**

> This has neither been brit-picked or beta'd.

You knew Mycroft was coming home today to celebrate your fifteenth birthday this weekend with the family, so you race home from school in order to spend as much time with him as possible. You bound up the stairs two at a time, rush down the hallway, and come to a full stop in front of his open bedroom.

"Mycroft! I'm so happy you're home. Oh!"

"Hello, there." said the unfamiliar, but extremely attractive, young man lounging on Mycroft's bed. "You must be Mycroft's sister." He rises up off of the bed and walks toward you, his hand extended out in front of him. "I'm Greg. Pleasure to meet you."

 

You reluctantly shake his hand. "What are you doing in my house?"

 

"Now, now, my dear sister. Please don't be rude." a familiar voice scolded behind you.

 

"Mycroft!" You turn toward him, wrap your arms around his waist, and squeeze him tightly.

 

Mycroft glares down at you, clearly embarrassed by your enthusiastic show of affection. You quickly release yourself from him and step back timidly.

 

"Mycroft? Are you sure she's _your_ sister?" Greg joked, surprised by your rather outlandish display of emotion. Your cheeks flush red at his cheeky comment.

 

"Very droll, Gregory. Yes, of course, she is my sister." Mycroft then grips your arm and turns you towards Greg so you're both facing him. He then says to you, "Darling sister, this is my friend Gregory from University. He will be staying here with us for the weekend."

 

Your eyes flick from Mycroft's to Greg's. "So, you'll be here for my birthday party, then? How _wonderful_. Excuse me." you say shortly. You turn on your heel, stalk out of the room petulantly, and go to your own room, slamming the door behind you.

 

You flop onto the bed and start to weep silently to yourself. How dare Mycroft bring some stranger home during your birthday weekend celebration! And then realization washes over you. Mycroft brought a _date_ to your birthday party. This only makes you weep even harder, tears streaming down your face like a waterfall. It's such an ugly cry. Snot building up and then dripping down your nose. Drool seeps out of your mouth, but you don't care. Mycroft has ruined your birthday and you will _never_ forgive him for that. And the worst part? You now know Mycroft will never love you the way you love him.

 

A knock on the door drags you out of your depression. "Just a minute" you yell at the door. You wipe your face sloppily with your hands, slide off of the bed, and amble over to the door. You cautiously open it and look up into the eyes of the one person you do not want to see right now.

 

"Mycroft." you say dejectedly. "Please leave me alone. I just want to be left alone."

 

Mycroft pushes his way in the room and closes the door behind him. "Sister mine, please tell me what is troubling you." He uses his thumb to wipe a tear away from your eye. You shrink away from his touch.

 

"Myc, please leave. I don't want to talk about it."

 

Mycroft bites his lip thoughtfully and says, "I know this is about Gregory being here. Please do not fret, dear sister. I have not forgotten about your birthday. I promise we will spend plenty of time together this weekend to celebrate."

 

Hearing this only upsets you even further and you twist away from him so he doesn't see your tears falling down your face. "Mycroft, please _leave_." you choke out.

 

He gingerly touches your shoulder and you pull away sharply as if you've been burned. "Darling, I..."

 

You turn forward to face him, anger building up inside of you. "What don't you understand? Get out of my room!"

 

You raise your fists in the air to beat at his chest to get him to leave, but he catches both of them by your wrists with his strong hands. You struggle against his grip, but to no avail.

 

"Let! Me! Go!" you scream at him. You attempt to wriggle away from him, but end up pulling him even closer to you. You don't realize how far you've moved until the back of your legs hit the bed and you both topple onto it. He's now on top of you, trapping you on the bed. He holds your wrists down on the bed, keeping them on either side of your head. You writhe underneath him; undulating your hips, trying to free yourself. Your skirt has risen slightly and you don't realize how much your squirming affects your brother until a soft groan escapes his lips. That's when you feel his clothed erection rubbing against your slowly dampening knickers. You lift your hips to increase the friction as he thrusts his body lightly to meet yours.

 

"Mycroft..." you moan softly.

 

He gazes down at you lovingly. Suddenly, his eyes go wide with fear when he realizes what he has been doing and who with. He then releases your wrists and quickly leaps off of you. He frantically tries to smooth down his trousers in an effort to not look too suspicious. Unfortunately for him, there is a noticeable wet spot smack dab on the front of them.

 

"Bugger" is all he says.

 

"Perhaps I can help. Just let me..."

 

"No!" he shouts as he back away from your touch. "I mean, I will take care of it."

 

"Myc?"

 

"I should not have... I mean, it is not your... I have to go. Apologies." And he hurriedly leaves the room, carefully closing the door on his way out.

 

You stare at the door. Your mind becomes a jumble of thoughts, but the most important one being, "Did that just really happen?"

 

********************************

 

Later that evening, you join the family downstairs for dinner. Mummy and Father are sitting the ends of the table, while you sit next to your little brother Sherlock. Mycroft is sitting across from you and Greg is sitting next to him. Stupid, gorgeous _Greg_. With his handsome face and his chocolate brown eyes and his sexy smile. Stupid arse. You hate him.

 

Sherlock leans over to you and whispers, "He's not his boyfriend. He's been staring at either your face or your breasts the entire time we've been sitting here."

 

"What are you talking about?" Or _who_ are you talking about, you think to yourself.

 

Sherlock was about to answer when our cook, Gennieve, brings in a small chocolate cake with lit candles and places it in front of you.

 

"Happy Birthday, m'dear." she says as she kisses your cheek.

 

"I thought your birthday was tomorrow?" Greg asked you inquiringly.

 

You open your mouth to answer, but Sherlock scoffs, "Her _party_ is tomorrow. Her birthday is _today_. Do your research."

 

"Sherlock, don't be rude." your mother says sharply. Then to you she says sweetly, "Darling, why don't you make a wish and blow out the candles."

 

You close your eyes and wish for Greg to disappear. When you open them again and see him still sitting next to Mycroft, you sigh deeply. Oh well. You then take a deep breath and blow out the candles.

 

Pieces are then sliced and placed in front of everyone. Father then raises his glass and wishes you a Happy Birthday. You thank him, pick up your fork, and tuck into the cake. As you go to take that first bite, you become aware of Mycroft's and Greg's eyes intently watching you. Seeing this as an opportunity to find out if what Sherlock said earlier is even remotely true; you then close your eyes, press your lips shut over the piece on the fork and slowly glide it out of your mouth.

 

"Mmmmm." you moan a bit louder than necessary. You open your eyes again and see them both staring at you. Mission accomplished, you think to yourself.

 

*********

 

After everything has been cleared, you excuse yourself from the table. You decide to head up to your room and just as you're about to grip the door knob, a hand touches your shoulder.

 

"Follow me." a velvetly soft voice whispers in your ear.

 

"Mycroft?"

 

He then leads you up the stairs to the attic, where you find Greg sitting on a blanket on the floor with a couple of bottles of wine and three glasses.

 

"What's all this?" you ask Mycroft cautiously.

 

You're expecting Mycroft to speak, but Greg's gravelly voice is the one you hear. "Mycroft told me that your birthday party was probably going to be more of a party for your parents than for you. So we decided you should have a little party of your own. What do you say?"

 

"I-I-I-I.. ummm..." you stammer. You nervously looked down at the bottles of wine. "Mycroft, are those from Father's cellar? What if he finds out?"

 

"Don't worry. Father won't even notice. Come. Have a seat."

 

"Mycroft, did you grab the rest of that cake?" Greg asks.

 

"Oh. Yes. It's right here."

 

So the three of us sat on the rather large blanket, drinking wine and eating cake. You discover that Greg isn't as awful as you initially thought he was. He's actually quite funny and a bit cheeky. The three of you had easily polished off the first bottle and were about to empty the second one, when the conversation became rather personal.

 

"So.... have you ever kissed a boy before?" Greg directs to you.

 

" _No_." you giggle.

 

"Would you like to?"

 

Before you can even answer, Greg leans in close to you and kisses you softly on your lips. The wine has gone to your head so you're unable to react as quickly as you'd like. Next thing you know, he's laying you down on the blanket. You become lost in it as the kiss becomes more feverish. You then feel a hand inching up your inner thigh. You initially thought it was Greg's, but realize his hand is currently occupied at the moment with your breasts. You gasp and pull yourself away from Greg's mouth as you feel long fingers slide into your knickers and slowly rub your clit.

 

"Mycroft?" you moan as you look up at your brother.

 

"Shh, sweetheart. Just relax and enjoy it. Doesn't it feels good, love? I bet it does." Greg coos. He then sits up, reaches under your dress and removes your knickers. "There, now. That's much easier, I'd say. Would you, Mycroft?"

 

"Yes, Gregory. Much better without those cumbersome knickers in the way." Mycroft's nimble fingers dip down between your folds to your dripping hole to gather your juices onto his fingers, and deftly glide back up to swollen clit, teasing you further.

 

You start to moan a bit louder. "Mycroft.. oh.. Myc.." You're cut off by Greg's lips pressing insistently against yours. His tongue slides around yours as he kisses you hard. You moan into his mouth as Mycroft's fingers work your clit faster. Your muffled moans only seem to encourage your older brother's fingers until you finally cum.

 

Greg then lifts himself up and runs his fingers through your hair. "How was that, gorgeous?"

 

You stare up at both of them; out of breath and satiated. "Wonderful..." is all you can say.

 

"Brilliant! Mycroft? Was that everything you hoped for?" Greg smirks.

 

You bite your lip, anxious to hear his response. You then gasp sharply as you watch Mycroft meticulously lick your juices off his fingers.

 

"Almost, Gregory." Mycroft gazes down at you as he palms his erection through his trousers.

 

"My dear sister, I would be ever so grateful if you could help me relieve my tension. After all, it is all your doing that I have been put in such a state of arousal. It seems only fair considering what has just transpired between us."

 

Mycroft then unbuttons his trousers, pulls down his zip, and slips out of his pants and trousers. His thick, hard cock bobs slightly.

 

You clap your hand to your mouth in shock. You've never actually seen a penis, much less one so big and your _brother's_.

 

You then gingerly sit up and inch yourself closer to him. Mycroft genuinely smiles at you, causing you to blush. You then wrap your hand around the base of his cock and start to stroke him gently. A soft groan of approval convinces you that you must be doing it correctly.

 

"Mmm... feels good." he sighs breathlessly.

 

Pre-cum starts to slowly weep out of the slit and drip down onto your hand. Curiosity gets the better of you, so you lean down and softly dab your tongue, trying to get a taste. Mycroft bucks his hips at your touch, clearly surprised by your action. Pleased by his reaction, you decided to continue laving your tongue over the head of his cock. You're not entirely sure of what you are doing, but Mycroft's fingers in your hair encourage you to continue.

 

"Oh my, little sister. That's...Fuck!" is what he shouts when you wrap your lips around the head of his cock and start sucking gently.

 

Suddenly, Greg's voice is coaching you in how to please your big brother orally.

 

"Love, try taking him down your throat a bit. Oh, that's very good. Just like that. Listen to your brother's noises. Do you hear how much he likes what you're doing to him?"

 

The combination of Mycroft's moaning and Greg's sultry voice in your ear instructing you in how to best suck off your brother is almost too much to bear.

 

"Now, trying stroking the rest of him with your hand if you can't get him all the way down your throat. Oh... _yes_. That's _very_ good. You're such a good girl, aren't you? So good at sucking your big brother's fat cock."

 

Hearing this only encourages you suck him even harder, your lips tightening themselves around him as you do so. Mycroft's hand is now gripping the top of your head, holding you there.

 

"Oh, baby sister.... that's.... fucking _hell_." he cries just as his cum shoots down your throat.

You try to swallow all of it, but, because you weren't prepared for it, some of it seeps out of your mouth and dribbles down your chin.

 

Greg, seeing your dilemma, motions you to sit up. He then grabs Mycroft's pocket square and uses it to clean off your face. "There we go. All better. Well, how was that, love? Everything you'd hoped for?"

 

You're about to answer him when your brother speaks up first. "Yes, Gregory. Perfect." Mycroft then pulls himself up off the floor and sits in front of you. He takes your face in his hands and kisses your lips firmly. "How was it for you, dear sister? Everything _you_ hoped for?" he asks sweetly.

 

"Yes. Perfect." you says as you repeat the word he used back to him. "But I still don't understand. When you were in my bedroom..." you trailed off.

 

"Ah. Mycroft? Why don't you let me take this for you?" Greg interjected.

 

Greg then explains how they had first met at uni and became fast friends. Of course, as their friendship developed, their conversations became much more personal and the subject of sex and girls was brought up. After much coaxing, and an entire bottle of wine, Mycroft finally admitted to him that there was a beautiful girl back home he would very much like to fuck. "Not _his_ word, mind you. He said it a lot more eloquently than I ever could. Though, I didn't know, at the time, that when he was talking about some beautiful girl back home, he literally meant _back_ _home_."

 

"But Mycroft, why did you run away? Didn't you see that I wanted it, too?" you asked.

 

"I was ashamed and had not expected you return my feelings as well. I then confided in Gregory about what had happened. That is when he admitted to me about his little quirk."

 

"Quirk? Mycroft, you're being far too kind. _Kink_ is more like it. When he told me about what had happened with you and how much he liked it, I became instantly hard."

 

Greg then bent down close to me and whispered "You see, I have a bit of kink about incest. Not for me, of course. But imagining other siblings fuck one another instantly gives me a huge erection. It all started when I ended up in three-way with these two gorgeous daughters of a friend of my mum's. The things I asked those girls to do to one another still brings a smile to my face. I'd been hooked ever since. Unfortunately, it's not so easy to find people willing to fuck their sister." Greg's nods his head in your direction. "Or _brother_. Well, until today. When Mycroft confessed to me what he had done, that's when I told him about my _interests_ and asked him relay to me about everything that happened in _explicit_ detail. When he told me how you, not only didn't stop him, but also incited him to continue, I knew I had to help him and _you_. That's when I came up with the plan to get you into the attic."

 

You stare at them dumbfounded. You hardly believe what you are hearing. You have so many questions, but the only thing you think to ask is "So, you're _not_ his boyfriend?"

 

"No, love. Just friends. Though, after seeing the two of you just now, I think I could be persuaded otherwise. Perhaps, we could even become a threesome. What do you say, hmmm?" Greg leers at you as he raises his eyebrows cheekily.

 

" _Gregory_. While I would much rather make arrangements to explore this matter further and in explicit detail, it will have to be for another time. I believe it is getting late and we should all get some sleep. Don't you agree, dear sister?"

 

"Yes, Myc."

 

You and Mycroft redress quickly as Greg tidied up the attic.

They then walk you to your room. Greg gives you a quick kiss, wishes you a good night, and heads toward the guestroom.

 

"Good night, Mycroft." you say quietly.

 

You go to turn the knob to your bedroom door, when Mycroft closes his hand around yours to stop you. You turn back toward him, looking at him expectantly. He does a quick glance down both sides of the hallway before he wraps his arm around to pull you closer to him and kisses you passionately. When he finally releases you, you fall back against the door breathless and flushed.

 

He then kisses you softly on the cheek. You feel his hot breath on your ear as he whispers, "Good night, sister _mine_. And Happy Birthday."

 

 

 

 

**Author's Note:**

> This is me putting my twisted fantasies of being Mycroft Holmes' younger sister into fan fiction form. I hadn't originally planned on sharing them with other people, but figured, why not?


End file.
